sstables: remove outdated comment
sstables: remove outdated comment

Signed-off-by: Raphael S. Carvalho <1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>

scylladb/scylla,raphaelsc/scylla,avikivity/scylla,duarten/scylla,kjniemi/scylla,duarten/scylla,raphaelsc/scylla,kjniemi/scylla,avikivity/scylla,raphaelsc/scylla,kjniemi/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla